I just finished the 4 inch RC and have been chasing down some problems now for the past few weeks. Was wondering if any one knew what this may be.
I am driving along and the trans is now making a clunking sound. It sounds like it is coming from under the stick shift and will do it in all gears and even when the clutch is in. Though with the clutch engaged, it slows and stops. Now it is a manual so, i am suspecting the shift fork? Also it now has a vibration when it hits about 53 mph.
Could the vibe be the tranny or time for a SYE? Any help or thoughts would be cool and thanks in advance.

It could and let me explain why. If the yoke is not seated far enough on the output shaft the clunking you feel could be the yoke rocking on the shaft. Your vibration comes from the yoke moving around or incorrect driveline angle.

It could and let me explain why. If the yoke is not seated far enough on the output shaft the clunking you feel could be the yoke rocking on the shaft. Your vibration comes from the yoke moving around or incorrect drive line angle.

That sounds very plausible and now that I am thinking the same thing, Get the drive shaft lengthened?

You could do that but you still need to make sure your drive line angle is correct. I have a 4.5" lift on mine but I run a SYE and driveshaft. A lot of people do this with 4"+ lifts. If you don't want to go that route or do not have the funds look up a poster by the name of ibuildembig. He is a fantastic person and very helpful. He also does not like the SYE/double cardian driveshaft set up and I believe all his rigs he builds, or most of them, he runs slip yoke. He can help you set yours up the right way. Good luck and keep us posted

You could do that but you still need to make sure your drive line angle is correct. I have a 4.5" lift on mine but I run a SYE and driveshaft. A lot of people do this with 4"+ lifts. If you don't want to go that route or do not have the funds look up a poster by the name of ibuildembig. He is a fantastic person and very helpful. He also does not like the SYE/double cardian driveshaft set up and I believe all his rigs he builds, or most of them, he runs slip yoke. He can help you set yours up the right way. Good luck and keep us posted

I just read the first few pages of your build thread and from what I have seen, my YJ is on it's way to you as we speak. Thanks for the advice and I am going out to take a photo here in a few, after I put coffee on.

Grab the yoke right where the u-joint cups are and see if it has excessive play on the shaft. Like move it up and down and side to side. See if it creates a quieter clunking noise. But it really doesn't look like its that far out to me though.

It makes the noise and sounds like it is deeper in the trans. When I got the jeep, the trans was rebuilt about a few years ago and no "real" miles have been put on the Jeep. It was used to tow behind an RV and go into town. The guy got it and put about 200 miles on it in 2 yrs so, I dont think any thing should have happen to the tranny but, you never know huh?
Should I take the u joints off at the top and see what happens when I play with it a little as in push it in a little and see what happens?

Just got back from the 4Wheel parts and Jeep show. I ended up getting a SYE and plan on putting it is next weekend. I am hoping that that was or is the noise I am hearing? I am sure it will help with the vibration. But, I can check things out while I am in there and see what is going on.

This is what the drive line looks like. I took the U joint off and played with it a little bit. There is a bit of play up and down and side to side. I did get the SYE yesterday but, I need to install it and see what the measurements are to have a CV joint and length put on the drive line. There is about 3/4 of an inch between all the way in and all the way out.

That clunk noise dose the shifter try to rotate clock wise when u accelerate out of first.
Ive just started hearing it on my GFs 90 wrangler and the stud mount was snapped behind the drivers side at the trany. The stud keeps the trany down.